Mu Li
StarOstrea gigas Thunb., Ostrea talienwhanensis Crosse, Ostrea rivularis Gould
Traditionally used for
- Headaches
- Dizziness
- Ears & hearing
- Cough & breathing
- Digestion
- Urinary & fluids
- Menstrual & women's health
- Sleep
- Mood & calm
- Nerves & recovery
- Heart & circulation
Cautions & contraindications
- Kidney conditions
☯ TCM Properties
Heavily settles and calms the Spirit; Calms the Liver, benefits Yin and anchors Floating Yang; Prevents the leakage of fluids; Softens hardness and d issipates nodules; Absorbs acidity and alleviates pain (calcined)
Traditional Chinese Uses
Mu Li (Concha Ostreae) is the calcium-rich shell of the oyster Ostrea (Crassostrea) gigas and allied species. Salty and cool, entering the Liver, Kidney and Gallbladder channels, it is one of the heavy, settling substances that anchor and calm. It subdues ascendant Liver Yang and extinguishes internal Wind for dizziness, headache, tinnitus, irritability and a flushed face, and it heavily settles the Spirit for palpitations, anxiety, restlessness and insomnia, classically paired with Long Gu (dragon bone).
Nourishing Yin, it treats Yin-deficiency night sweats and tremors, and softens hardness to dissipate phlegm nodules such as scrofula and goiter, combined with Xuan Shen and Bei Mu. Calcined, its astringency restrains leakage of fluids, checking spontaneous and night sweating, spermatorrhea, leukorrhea and uterine bleeding, and it absorbs acid to relieve stomach pain and reflux. It appears in Zhen Gan Xi Feng Tang and Gui Zhi Jia Long Gu Mu Li Tang.
Used In Formulas (38)
Relationships
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Botanical Description
Mu Li is not a plant but the dried shell of oysters in the genus Ostrea, principally Ostrea gigas (Crassostrea gigas), O. talienwhanensis, and O. rivularis, harvested along the coasts of China. These bivalve mollusks produce thick, hard, irregularly oval to elongated shells composed of layered calcium carbonate, typically eight to thirty centimeters across, with a deeply concave lower valve and a flatter upper valve. The exterior is rough, scaly, and irregularly laminated, often encrusted with marine growths, ranging in color from greyish-white to purple-brown. The interior is smooth, pearlescent, and porcelain-white, sometimes with a darker muscle scar. After collection the shells are washed clean of soft tissue, sun-dried, and broken or calcined for medicinal preparation; the substance consists almost entirely of calcium carbonate with trace minerals.
Active Constituents
Calcium carbonate
Inorganic carbonate saltConcentration: Major component, above ~94% by weight
The principal effective ingredient of oyster shell; provides antacid (acid-neutralizing), astringent and hardness-softening actions and is the source of bioavailable calcium.
Calcium phosphate
Inorganic phosphate saltConcentration: Minor mineral component
Contributes additional mineral content supporting bone-related and astringent uses.
Calcium sulfate
Inorganic sulfate saltConcentration: Trace mineral component
Minor inorganic constituent of the shell matrix.
Conchiolin (organic shell matrix protein)
Structural protein / amino acidsConcentration: Organic matrix fraction of the shell
Insoluble protein matrix binding the calcium minerals; releases amino acids on processing and is associated with the shell's traditional calming and astringent actions.
Trace minerals (magnesium, iron, aluminium, silicon, zinc, strontium)
Trace elementsConcentration: Trace amounts
Trace elements incorporated in the shell that may contribute minor cofactor and mineral supplementation effects.
⚠ Drug Interactions
Tetracycline and fluoroquinolone antibiotics
The high calcium-carbonate content chelates tetracyclines and fluoroquinolones in the gut, forming insoluble complexes that markedly reduce antibiotic absorption.
Clinical note: Separate administration by at least 2-4 hours from these antibiotics.
Levothyroxine (thyroid hormone)
Calcium carbonate binds levothyroxine in the gastrointestinal tract, decreasing its absorption and potentially reducing therapeutic effect.
Clinical note: Take levothyroxine at least 4 hours apart from calcium-containing products.
Oral bisphosphonates and iron salts
Calcium forms poorly absorbed complexes with bisphosphonates and with oral iron, reducing bioavailability of the co-administered drug.
Clinical note: Separate dosing; take bisphosphonates on an empty stomach well before calcium.
Acid-dependent drugs (raised gastric pH)
As an antacid, calcium carbonate raises gastric pH, which can reduce absorption of drugs requiring an acidic environment (e.g., certain azole antifungals, atazanavir).
Clinical note: Separate administration and monitor efficacy of pH-dependent medications.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction (pre-decocted / bagged) | 9–30 g | Daily | — | — | 中国药典 2020 monograph 【牡蛎】【用法与用量】9～30g，先煎。 【性味与归经】咸，微寒。归肝、胆、肾经。 — Matched to ChP by romanised drug name (pinyin 'Mu Li' → 牡蛎); the romanisation is unique across all 649 ChP monographs, and the match was cross-checked against this record's own TCM temperature. Quoted verbatim. |
Preparation Methods
Decoction, crushed and pre-decocted (raw)
Parts: shell
Raw oyster shell (15-30 g, up to larger doses) is crushed and decocted first (about 20-30 minutes before other herbs) to extract the minerals. Raw Mu Li is preferred to calm the Liver, anchor floating Yang and calm the spirit.
Calcined (duan) decoction
Parts: shell
The shell is calcined until brittle, then crushed and pre-decocted. Calcined Mu Li is preferred for astringent actions - absorbing acidity, restraining sweating and leakage of fluids.
Dui Yao — Herb Pairs
The classical two-herb combinations this herb appears in, each with an action neither herb has alone.
Astringing sweat combined with tonifying qi and securing the exterior, which stops spontaneous and night sweating from deficiency.
Spontaneous sweating worse at night with palpitations from exterior insecurity.
Core pair of a classical formula — Mu Li San, Tai Ping Hui Min He Ji Ju Fang
Two heavy settling substances that together anchor floating yang, calm the spirit and astringe leakage, more effectively than either alone.
Palpitations, insomnia, spontaneous or night sweating and seminal emission from yin-yang disharmony.
Core pair of a classical formula — Gui Zhi Jia Long Gu Mu Li Tang, Jin Gui Yao Lue (Zhang Zhongjing)
A herb that specifically stops sweating combined with a heavy astringent mineral that secures the exterior and restrains yin, the pair stops spontaneous and night sweating.
Used with Huang Qi. Not for sweating from an exterior pathogen.
Core pair of a classical formula — Mu Li San, Tai Ping Hui Min He Ji Ju Fang
Transforms phlegm and dissipates clumps while softening hardness, together reducing phlegm nodules.
Core pair of a classical formula — Xiao Luo Wan, Yi Xue Xin Wu (Cheng Guopeng, 1732)
⚠ Safety & Contraindications
- Kidney conditions
Contraindications
It is not suitable for taking too much or for a long time, and its use is prohibited in patients with spontaneous seminal emission due to deficiency-cold of the kidney.
Source: Xi S, Gong Y. Essentials of Chinese Materia Medica and Medical Formulas. Academic Press/Elsevier, 2017, pp. 307–310.
Historical Texts
Shen Nong Ben Cao Jing (Divine Farmer's Materia Medica)
Han dynasty (c. 200 CE)Shang Han Lun (Treatise on Cold Damage), Zhang Zhongjing
Eastern Han dynasty (c. 200 CE)References
- Zhang Y, Li J, Wu Z, et al.. Chemical Profiles and Identification of Key Compound Caffeine in Marine-Derived Traditional Chinese Medicine Ostreae concha . Marine Drugs (2012) [DOI]
This information is for educational purposes only and is not intended to replace professional medical advice. Always consult a qualified healthcare provider before using any herbal remedy, especially if you are pregnant, nursing, or taking medications.
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